private void DrawLine(VisualTextLine line) {
if (line.Index < visuals.Count) {
visuals.Insert(line.Index, line);
visuals.RemoveAt(line.Index + 1);
line.Draw();
} else {
visuals.Add(line);
line.Draw();
}
}
private void RedrawCollapsedLine(VisualTextLine collapsedLine, int line) {
if (line >= visuals.Count) {
visuals.Add(null);
} else {
visuals[line] = null;
}
visuals[line] = collapsedLine;
collapsedLine.Draw();
}
public IEnumerable<VisualTextLine> GetLinesToRedrawAfterCollapse(IReadOnlyList<VisualTextLine> visuals, VisualTextLine collapsedLine, TextRange range) {
var linesToRedraw = new List<VisualTextLine>();
if (range.StartPosition.Line == range.EndPosition.Line) {
return linesToRedraw;
}
var collapseEndLine = range.EndPosition.Line;
for (int i = collapseEndLine + 1, newIndex = collapsedLine.Index + 1; i < visuals.Count; i++, newIndex++) {
var line = visuals[i].CloneWithIndexChange(newIndex);
linesToRedraw.Add(line);
}
return linesToRedraw;
}
private VisualTextLine GetPartialLineBeforeCollapse(IEnumerable<CharInfo> charInfos, VisualTextLine line, int startIndex, int count) {
var collapseInfo = charInfos.First(info => !info.IsCharacter);
var contents = line.RenderedText;
var textBeforeCollapse = string.Empty;
if (collapseInfo.PrevCharPosition.Column >= startIndex) {
textBeforeCollapse = contents.Substring(startIndex, collapseInfo.PrevCharPosition.Column);
} else {
textBeforeCollapse = contents.Substring(startIndex);
}
var diff = 0;
if (startIndex + count >= collapseInfo.NextCharPosition.Column) {
diff = (startIndex + count) - collapseInfo.NextCharPosition.Column;
}
var textAfterCollapse = string.Join("", contents.Skip(collapseInfo.NextCharPosition.Column).Take(diff));
return VisualTextLine.Create(textBeforeCollapse + textAfterCollapse, line.Index);
}
private VisualTextLine GetPartialLineAfterCollapse(VisualTextLine line, int startIndex, int count) {
var firstPart = line.RenderedText.Substring(startIndex, count);
return VisualTextLine.Create(firstPart, line.Index);
}
private VisualTextLine CutStandardLine(VisualTextLine line, int startIndex, int count) {
var contents = line.GetStringContents()[0];
var newText = string.Empty;
if (startIndex + count == line.Length) {
newText = contents.Substring(startIndex);
} else {
newText = contents.Substring(startIndex, count - startIndex);
}
return VisualTextLine.Create(newText, line.Index);
}
private VisualTextLine Cut(VisualTextLine line, int startIndex, int? count = null) {
var substringLength = count == null ? line.Length - startIndex : count.Value;
if (line is CollapsedVisualTextLine) {
var charInfos = Enumerable.Range(startIndex, substringLength).Select(index => line.GetCharInfoAt(index));
if (charInfos.Any(info => !info.IsCharacter)) {
return GetPartialLineBeforeCollapse(charInfos, line, startIndex, substringLength);
} else {
return GetPartialLineAfterCollapse(line, startIndex, substringLength);
}
} else {
return CutStandardLine(line, startIndex, substringLength);
}
}
private int[] GetCollapseSelectionRange(TextPosition clickPosition, VisualTextLine activeLine, int lineLength) {
var startColumn = clickPosition.Column;
var endColumn = clickPosition.Column;
if (endColumn + 1 <= lineLength) {
endColumn += 1;
} else {
startColumn -= 1;
}
// move left from current position
for (var i = clickPosition.Column; i >= 0; i--) {
var charInfo = activeLine.GetCharInfoAt(i);
if (!charInfo.IsCharacter && !char.IsLetterOrDigit(charInfo.Text[0])) {
startColumn = i;
} else {
break;
}
}
// move right from current position
for (var i = clickPosition.Column; i < lineLength; i++) {
var charInfo = activeLine.GetCharInfoAt(i);
if (!charInfo.IsCharacter && !char.IsLetterOrDigit(charInfo.Text[0])) {
endColumn = i + 1;
} else {
break;
}
}
return new[] { startColumn, endColumn };
}
